The NICHD, as delegated by the NIH, is responsible for implementing the Congressionally-mandated Best Pharmaceuticals for Children Act of 2002, as reauthorized in 2007. The NICHD is responsible for the performance of clinical trials of priority, [unreadable]off patent[unreadable] drugs that are used in children but that lack sufficient pediatric labeling. One such drug is oral baclofen. The purpose of this contract is to conduct clinical research studies on pediatric use of oral baclofen that will provide data to FDA to support pediatric drug labeling of oral baclofen for spacticity of cerebral palsy. Cerebral palsy refers to a group of neurological disorders affecting control of movement and posture and which limit activity. The brain may be injured or develop abnormally during pregnancy, birth or in early childhood. The causes of cerebral palsy are not well understood. There is no known cure for CP. Medical intervention is limited to the treatment and prevention of complications arising from CP's effects. Oral baclofen is a drug that is sometimes used to treat the movement disorders arising from cerebral palsy. However, information regarding dosing, pharmokinetic parameters, effectiveness, and safety of this important drug in children and adolescents is incomplete. Up to four studies will be conducted under this contract to determine if oral baclofen is safe and effective in a pediatric population with cerebral palsy.